1. Field of the Invention
The present invention relates to a manufacturing method of a semiconductor device, an adhesive sheet used in the same method, and a semiconductor device obtained by the same method.
2. Description of the Related Art
In order to correspond to the demand of microminiaturization and realization of high functionality of a semiconductor device, the wiring width of a power line and the interval between signal lines arranged on the entire area of the major surface of a semiconductor chip (a semiconductor element) have been becoming narrow. Thereby, an increase of impedance and interference of signals between signal lines of different nodes occur, which become the cause of impeding the demonstration of sufficient performance in operation speed, degree of allowance in operation voltage, anti-electrostatic breakdown strength, and the like in the semiconductor chip. In order to solve these problems, a package structure is proposed in which the semiconductor element is layered (for example, refer to Japanese Patent Application Laid-Open (JP-A) Nos. 55-111151 and 2002-261233).
On the other hand, as a substance used when a semiconductor element is fixed onto a substrate or the like, an example using a thermosetting paste resin (for example, refer to JP-A No. 2002-179769) and an example using an adhesive sheet in which a thermoplastic resin and a thermosetting resin are combined (for example, refer to JP-A Nos. 2002-261233 and 2000-104040) are proposed.
In the conventional manufacturing method of a semiconductor device, an adhesive sheet or an adhesive is used at the time of adhesion of a semiconductor element and a substrate, a lead frame, or a semiconductor element. The adhesion is performed by compression bonding (die attaching) a semiconductor element and a substrate or the like, and then by curing an adhesive sheet or the like in a heating step. Further, wires are bonded to connect the semiconductor element and the substrate electrically, and then sealing with a sealing resin is performed by molding with the sealing resin and curing.
In recent years, the thickness of a semiconductor element has become thinner from the conventional thickness of 200 μm to less than 200 μm, and further to 100 μm or less, associated with thinning and miniaturization of the semiconductor element. When die attaching is performed using a semiconductor element of 100 μm or less, a warp may occur in the semiconductor element. As a result, there are cases where a gap is generated between the semiconductor element after die attaching and the adherend. When a semiconductor device is manufactured with a gap remaining, there is a problem that reliability of the device decreases.